GB2163608A

GB2163608A - Spinning or twisting element with individual drive

Info

Publication number: GB2163608A
Application number: GB08519963A
Authority: GB
Inventors: Ernst Braun
Original assignee: SKF Textilmaschinen Komponenten GmbH
Current assignee: SKF Textilmaschinen Komponenten GmbH
Priority date: 1984-08-11
Filing date: 1985-08-08
Publication date: 1986-02-26
Also published as: DE3429651C1; US4886991A; IT8521723A0; GB2163608B; DD238251A5; CH666700A5; IN161870B; IT1185309B; JPH0318418B2; GB8519963D0; JPS6147831A

Description

1 GB2163608A 1

SPECIFICATION

Spinning or twisting element with individual drive The invention relates to a spinning or twisting element of a textile machine with individual drive by means of an asynchronous motor fed through a converter; the rotor of the motor is connected to a shaft of the spinning or twisting element.

Such a drive has already been described in Patent Specification DE2644749. In practical use, the introduction of individual drives in ring spinning or open-end rotor spinning machines with conventional asynchronous motors was doomed to failure because of the long run-up time, poor efficiency and deficient synchronization of the spinning places.

The subject of the invention is a drive motor for low power (range 20 to 200 watts) and high frequency (range 200 to 2000 Hz) for the individual drive of spinning or twisting elements. Such a motor should have optimum efficiency, should be capable of a quick run-up to nominal frequency when directly connected and should meet the requirement of synchronization.

The invention provides a spinning or twist- ing element with individual drive by means of an asynchronous motor fed through a converter, the motor rotor being connected to a shaft of the spinning or twisting element, wherein the stator of the asynchronous motor has at least 24 grooves and that the thickness 100 of the stator lamination and of the rotor lamination is less than 0.3mm.

The development of the stator with 24 grooves according to the invention enables a high torque to be produced even in the case of a small-sized motor. Thus the motor exhibits low slip and this results in good synchronization of the spinning places. The use of extremely thin stator laminations and rotor laminations ensure optimum efficiency for small motors.

Preferably the rotor is a double-cage rotor, and the starting torque of the motor is thus increased and at the same time, during oper- ation at normal rating, the rotor resistance is reduced. This helps to prevent motor slip, resulting in particularly good synchronization of the spinning places, which fulfills the requirements of spinning technology.

An embodiment of the invention will now be described by way of example and with reference to the accompanying drawings, of which:

Figure 1 shows a stator lamination, and Figure 2 shows a rotor lamination.

Conventionally, the asynchronous motor is composed of a stator and a rotor. The rotor is firmly connected to a spindle shaft or an open-end spinning rotor.

The stator comprises a large number of su- 0 perposed stator laminations 1 which are insulated by a lacquer coating. The stator laminations are combined to form a bundle of laminations by means of rivets inserted in rivet holes 3. Recesses 2 are punched in the inner circumference to form grooves in the bundle of laminations. The winding is drawn into these grooves in known manner. The stator lamination 1 is here provided with at least 24 recesses, since it is designed to have a corresponding minimum quantity of grooves so as to be able to produce a high torque even for a given small size of the asynchronous motor.

The rotor is also composed of a large num- ber of superposed lacquer-coated rotor lamina7 tions 4. Recesses 5 and 6 punched in the rotor lamination form grooves in the superposed rotor laminations. These grooves are filled with aluminium so as to form a cage rotor. The outside bars (recesses 5) are designated---Startingbar--- and the inner ones---operational bars---. This arrangement takes account of the fact that in the case of higher operational frequencies, even with small motors, the current displacement from the operating cage to the starting cage takes it full effect, which is unimportant with this size of motor at normal frequency. In this way the inner operational bars (recesses 6) are only fully effective at operating speed and reduce the slip. By using a double- cage rotor the starting torque is increased and the individual drive is thus able to be run-up more quickly. This is specially the case if the motor is directly connected to the nominal frequency.

The stator laminations 1 and the rotor laminations 4 are thinner than 0.3 mm. With highfrequency motors this provides the advantage that only low eddy current loss occurs during 105 magnetic reversal.

Claims

1. A spinning or twisting element with individual drive by means of an asynchronous motor fed through a converter, the motor rotor being connected to a shaft of the spinning or twisting element, wherein the stator of the asynchronous motor has at least 24 grooves and that the thickness of the stator lamination and of the rotor lamination is less than 0.3 mm.

2. A spinning or twisting element with individual drive as claimed in Claim 1, wherein the rotor of the asynchronous motor is a dou- ble-cage rotor.

3. A spinning or twisting element with individual drive substantially as herein described with reference to and as shown in the accompanying drawings.

Printed in the United Kingdom for Her Majesty's Stationery Office, Dd 8818935, 1986, 4235. Published at The Patent Office, 25 Southampton Buildings, London, WC2A 'I AY, from which copies may be obtained.